“That’s not progressive?” reads a sign held up by members of the Patrolmen’s Benevolent Association in the lobby of an Iowa hotel where Mayor de Blasio is staying.

DES MOINES — Mayor de Blasio hopes to get a warm reception from progressives in Iowa, but his trip was first met by New York City labor union representatives who traveled to the Midwest to roll out the unwelcome wagon for him.

Members of the Patrolmen’s Benevolent Association made the 1,000-mile trek to stalk the lobby at de Blasio’s Marriott hotel. They came outfitted with posters and fliers blasting the mayor over their salary negotiations and insisting he is neither friend to labor nor a progressive. To drive home the point, a giant mobile billboard sat parked outside with the same messages.

The Transport Workers Union, allied with de Blasio nemesis Gov. Cuomo, took out a full-page ad, which costs at least $8,650, according to an ad rep, in The Des Moines Register saying: “He claims he’s a true-blue Progressive. But take a closer look. He’s a fake, this Phony Bill is no Bernie Sanders!”

Back home, the Correction Officers Benevolent Association, a third union that has often feuded with the mayor, sought to capitalize on his jaunt with a statement accusing him of being “missing in action” from his “real job” — to instead “begin his political pursuit of winning the presidency.”

On NY1’s “Inside City Hall,” Monday night, de Blasio said he expected the city to reach a deal that was fair for the PBA and taxpayers, noting an uncertain fiscal future for the city with the federal tax overhaul pending.

“Whatever they want to do in New York or out of, that’s their rights as American citizens,” he said. “We have dealt very fairly with labor.”

Mayoral spokesman Eric Phillips amplified the sentiment Tuesday.

“The mayor’s focus is on getting fair deals for our workers and taxpayers,” Phillips said. “Nothing will distract from that approach.”

Mayor de Blasio is hoping to get a warm reception from progressives in Iowa.

(Theodore Parisienne/for New York Daily News)

The unions’ three-pronged attack came as Hizzoner landed in Iowa — home to the nation’s first presidential caucus — on Tuesday afternoon to give a dinner speech to a group called Progress Iowa in the evening. De Blasio didn’t run into the PBA at his hotel, instead heading straight to a closed-door sit-down with local mayors before a planned press conference and then the dinner.

But the PBA promises to be hard to miss there, with plans to demonstrate outside.

“We’re here to set the record straight and show that Bill de Blasio is a liar, he’s not a friend of labor, and look at what he’s doing to us, and that’s the real Bill de Blasio,” John Puglissi, the PBA first vice president, said in the hotel lobby. “Wherever he goes, we plan on following him around, and we’re gonna let — whether it’s his constituents, other parties, people, towns, wherever he wants to go across the country, we’re gonna follow them and let them know what the real Bill de Blasio is all about.”

The PBA objects to what it says is a contract proposal from the city that includes “three-and-a-half years of zeroes,” in addition to cuts to pensions and health care. The union, which represents rank-and-file cops, has been working without a contract since the summer, after previously inking a handshake deal in January that was retroactive and covered members through fiscal year 2017.

The TWU, meanwhile, has been hammering de Blasio over funding for the subway system — alongside Cuomo, who has insisted the city should pay half of a rescue plan for the agency. In its ad, which depicts the mayor dressed up in a three-dollar bill suit, they accuse him of “anti-worker, anti-union policies” like arresting bus drivers under the “Right of Way” law making it a misdemeanor to fail to yield and then strike a pedestrian. They also slam him for deals for real estate developers and his attempts to “decimate the historic horse-carriage industry.”

“This is an all granola, no-grit brand of phony progressivism and it will not benefit America’s working families,” TWU International President John Samuelsen said in a statement. “Mayor de Blasio is very quick to throw his so-called principles in the gutter when it’s politically expedient. He’s a situational progressive, and definitely not an ardent trade union supporter. De Blasio is as phony as a three-dollar bill!”

Elias Husamudeen, the head of COBA, which represents correction officers on Rikers Island and other city jails, said in a statement the trip was part of a “pattern by the mayor,” whom he accused of missing a funeral for a correction officer. He also said the mayor has been “absent” in the aftermath of correction officers being slashed and beaten, and knocked him for not showing up to an indictment of 15 inmates in a Thanksgiving beating of a captain.

“Our message to the Mayor is this: ‘Enough is enough, do your damn job already!’ ” Husamudeen said in a statement. “Protect the 10,000 correction officers, who comprise the second-largest uniformed force in this city and who keep this city safe.”